Expression of Fibronectin and its Receptor in Some Tumour Cell Lines and in HIV-1-Infected Cells

Abstract

The aim of our study was to evaluate the levels of fibronectin (FN) and its classic receptor (FNR) in various transformed cells lines, especially of leukemic origin, and also the influence of HIV-1 replication on the expression of these proteins (in particular on H9-V cells, chronically infected with HIV-1, and acutely infected MT-4 cells). Monoclonal antibodies were used for indirect immunofluorescence tests; the fluorescein-conjugated recombinant p14, the product of the HIV gene tat, was used as a molecular probe. The results demonstrated a high variability of FN and FNR expression among the various cellular lines studied. Moreover, deficits of such adhesive proteins did not necessarily correlate with a severe reduction of the corresponding receptor. HIV-1 replication in MT-4 and H9-V cells increased the expression of FNR. This seems to correlate with p14-induced phenomena because pretreatment of H9-V cells with recombinant p14 showed an enhancing effect on the expression of this receptor.

Quantitative Study of beta 1 -Integrin Expression and Fibronectin Interaction Profile of T Lymphocytes in Vitro Infected with HIV

“…This slight decrease may cor-respond to a decrease in the response to IL-2, a cytokine that maintains integrin expression, as HIV infection decreases CD25 expression by T lymphocytes. 39,40 Our finding that HIV does not affect b 1 -integrin expression differs from other reports, 23,24 describing an increase in the lymphocyte surface expression of CD49e and CD29 chains on HIV infection in vitro, associated with an increase in adhesion to FN-coated plastic. This apparent difference in results may be due to our experiments being performed with primary PBLs, whereas the others were carried out with H9 or MT4 T cell lines.…”

“…Previous studies have demonstrated that the level of expression of CD49e and CD29 chains is higher than normal on chronically infected H9 T cells, 23,24 and on acutely infected MT4 CD4 1 T cells. 24 This effect is probably dependent on the viral protein Tat 25 and may thus respond to autocrine or paracrine mechanisms.…”

“…Previous studies have demonstrated that the level of expression of CD49e and CD29 chains is higher than normal on chronically infected H9 T cells, 23,24 and on acutely infected MT4 CD4 1 T cells. 24 This effect is probably dependent on the viral protein Tat 25 and may thus respond to autocrine or paracrine mechanisms. In contrast, Marodon et al 26 described constant levels of CD29 and CD49d in peripheral blood lymphocytes expressing a HIV-heat stable antigen reporter virus.…”

Apoptotic DNA fragmentation, and itsin vitro prevention by nicotinamide, in lymphocytes from HIV-1-seropositive patients and in HIV-1-infected MT-4 cells

“…15 Brie¯y, cells were suspended at 5 Â 10 5 ml À 1 . Of these suspensions, 2 ml portions were centrifuged for 10 min at 140 g in 50-ml centrifuge tubes (Nunc).…”